Light-sensitive silver halide color-photographic material

ABSTRACT

AN ULTRAVIOLET ABSORBER OF THE HYDROXYBENZOTRIAZOLE TYPE IS STABLY INCORPORATED INTO A LIGHT-SENSITIVE SILVER HALIDE COLOR-PHOTOGRAPHIC MATERIAL SO AS TO IMPROVE THE RESULTING COLORED DYE IMAGE IN LIGHT FASTNESS.

United States Patent s 698 907 LIGHT-SENSITIVE s1LvER HALIDE COLOR- rnoroomrnc MATERIAL Shut Sato, Tokyo, Sadao Sugita, Hanno, and Tomio US. CI. 96-44 R 5 Claims ABSTRACT OF THE DISCLOSURE An ultraviolet absorber of the hydroxybenzotriazole type is stably incorporated into a light-sensitive silver halide color-photographic material so as to improve the resulting colored dye image in light fastness.

It is well known that the colored dye image of a color photograph obtained by color development of a lightsensitive silver halide color-photographic material is adversely atfected particularly by UV-light and tends to fade when subjected to UV-irradiation. Further, a color former remaining in the emulsion layer of a light-sensitive'silver halide color photographic material after color development forms stains by the action of UV-light. In order to prevent the colored dye image of a color photograph from fading and from staining due to residual color former, there has heretofore been adopted a procedure to incorporate a UV-absorber into one or more of the layers (e.g. light-sensitive layer, interlayers, protective layers, etc.) of a light-sensitive silver halide color-photographic material. UV-absorber to be used for such purpose as mentioned above should be colorless or substantially colorless, in general, and be inert to other photographic additives and various treating liquids, and are required to be excellent in UV-absorbing property and stable to UV-light. Among many UV-absorbers proposed hitherto, those of the hydroxybenzotriazole type have been known as excellent UV-absorbers.

Generally, the hydroxybenzotriazole type UV-absorbers display their excellent UV-absorbing properties when dispersed according to the solvent dispersion method into the layers constituting light-sensitive color-photographic materials. As is well known, the solvent dispersion method is effective for finely and uniformly dispersing a non-diffusing aromatic compound in non-crystalline form into a hydrophilic binder, and is carried out in such a manner that a non-diffusing aromatic compound is added to an organic solvent comprising a difiicultly watersoluble high boiling solvent or a mixture thereof with a low boiling solvent and then dispersed in a hydrophilic binder. In order to adopt this solvent dispersion method, therefore, it is necesary that the hydroxybenzotriazole type UV-absorber has excellent solubility for the abovementioned organic solvent. For this reason, there has been adopted such a procedure that an oleophilic group of a relatively long chain is introduced into the hydroxybenzotriazole type UV-absorber to enhance the solubility thereof for said organic solvent. Due to introduction of 3,698,907 Patented Oct. 17, 1972 the oleophilic group, however, the UV-absorber is increased in molecular weight, but does not change in fundamental structure for UV-absorption. Accordingly, the UV-absorber cannot display the same UV-absorbing effect as attained before introduction of the oleophilic group, unless the amount of the UV-absorber is increased. If the amount of the UV-absorber is increased, however, there are brought about coloration, staining and the like drawbacks.

As the result of extensive studies, we have found that when an excellent hydroxybenzotriazole type UV-absorber of the general Formula I,

wherein R R R R and R are individually a hydrogen or a halogen atom, or an alkyl, cycloalkyl, alkoxy, aryl, carbalkoxy or alkylsulfonic group, is used in combination with a compound of the general Formula II,

wherein R and R are individually hydrogen, alkyl, alkoxy or acyl group; X is -C() or COO--; and n is 1 or 2, the UV-absorber shows prominent solubility for an organic solvent comprising a diflicultly watermiscible high boiling solvent or a mixture thereof with a low boiling solvent. According to the present invention, therefore, groups R R and R in the above-mentioned general Formula I may be less in number of carbon atoms, so that when incorporated with the above-mentioned hydroxybenzotriazole type UV-absorber, a lightsensitive silver halide photographic material can be prevented from deterioration in photographic properties due to increase in amount of UV-absorber or organic solvent, can retain the UV-absorber stably and can give a colored dye image which has been improved in light fastness.

In order to effectively display the UV-absorbing property of the UV-absorber of the general Formula I, it is desirable that each of the groups R R and R; has 6 or less carbon atoms and the sum of the carbon atoms of R R and R is 8 or less. A hydroxybenzotriazole type UV-absorber containing substituents having such a small number of carbon atoms can also be dissolved quite successfully in the organic solvent used in the solvent dispersion method due to the presence of a compound of the general Formula II.

Table 1 set forth below shows the results obtained by comparing the amount, necessary for dissolving 1 g. of a UV-absorber of the general Formula I, of a solvent comprising dibutyl phthalate alone with that of a solvent comprising a 1:1 mixture of dibutyl phthalate and a compound of the general Formula II, and the results obtained by measuring the time required for each of the resulting solution to deposit the UV-absorber when stored at C.

N OH

TABLE 1 Solvent 1:1 mixture of- Exemplified corn- Exemplifled com- Exemplified com- Exempllfied eom- Dibutyl phthalate pound 8 and dibutyl pound 11 and dibutyl pound 16 and dibutyl pound 21 and dibutyl alone phthalate phthalate phthalate phthalate Required Deposi- Required Deposl- Required Deposi- Required Deposi- Required Deposiamount, tion time, amount, tion time, amount, tlon time, amount, tlon time, amount, tion time, UV-absorber of Formula I cc. mins. cc. ruins cc. mins. 00. mins. cc. ns.

Exemplified compound:

Further, Table 2 shows the results obtained by measuring the variation in time required for deposition of UV- fear of deposition of the UV-absorber or no such fear as coloration or staining due to increase in amount of the absorber when each of the solvents set forth in Table 1 UV-absorber; and there is no such fear'that the resulting was used in excess of the required amount.

emulsion layer is deteriorated in physical properties or TABLE 2 Solvent 1:1 mixture of- Exemplified oom- Exemplified com- Exemplified com- Exemplified com- Dibutyl phthalate pound 8 and dibutyl pound 11 and dibutyl pound 16 and dibutyl pound 21 and dibutyl alone phthalate phthalate phthalate phthalate Required Deposi- Required Deposl- Required Deposl- Required Deposi- Required Deposiamount, tion time, amount, tion time, amount, tion time, amount, tion time, amount, tion time, UV absorber of Formula I cc. mins. co. us. cc mins. cc mins. cc. mins.

Exemplified compound:

The exemplified compounds shown in Tables 1 and 2 are set forth later.

From Tables 1 and 2, it is clearly understood that a hydroxybenzotriazole type UV-absorber of the Formula I, which contains substituents less in number of carbon atoms and which is excellent in UV-absorbing property, can be dissolved quite successfully and stably in an organic solvent used in the solvent dispersion method due to the presence of a compound of the general Formula II. Accordingly, when the hydroxybenzotriazole type UV-absorber of the general Formula I is used in the solvent dispersion method in combination with the compound of the general Formula II, there can be attained such advantages that not only the amount of the organic solvent used but also the amount of the UV-absorber can be decreased; the UV-absorber can be stably dispersed without any fear of deposition, so that even during the prepara tion and storage of a light-sensitive silver halide colorphotographic material incorporated therewith, there is no inhibited from penetration of various photographic treating liquids due to increase in amount of the organic solvent used.

Typical examples of the hydroxybenzotriazole type UV- absorbers of the general Formula I are as follows:

These, however, are not limitative, and all benzotriazole type UV-absorbers represented by the general Formula I can be effectively used in the present invention.

Typical examples of the compounds of the general Formula II are as set forth in Table 3, though these are not limitative.

TABLE 3-C0ntinued Substituents in Formula II For the incorporation of the above-mentioned compounds of the general Formulas I and II into a light-sensitive silver halide color-photographic material, there may be adopted the ordinary solvent dispersion method. For example, a light-sensitive silver halide color-photographic material incorporated with said compounds may be prepared by dissolving a mixture of the compounds of the Formula I and II in suitable proportions in a difficultly water-riscible high boiling solvent, if necessary in admixture with a low boiling solvent as an auxiliary solvent, dispersing the resulting solution into an aqueous gelatin solution by use of a suitable surface active agent, adding the thus formed dispersion to an aqueous gelatin solution for forming a silver halide photographic emulsion layer or other layer, and then subjecting the resulting mixture to ordinary process for preparing a light-sensitive silver halide color-photographic material. In case a low boiling solvent has been used as the auxiliary solvent, it may be removed by the water-washing treatment carried out after cooling, setting and finely dividing the dispersion, by the heating of the dispersion or by the drying treatment carried out during preparation of the photographic material.

The silver halide photographic emulsion to he employed in the above case may be any of silver chloride, silver bromide and silver iodobromide emulsions. These emulsions may have been subjected to gold, sulfur or the like chemical sensitization and to color sensitization, and may have been incorporated with stabilizers, vehicles, hardeners, couplers, anti-stain agents, brightening agents and antioxidants.

The amount of the UV-absorber of the general Formula I is adequately 1 to mg. per 100 cm. of the area to be coated, and the amount of the compound of the general Formula II is desirably 0.1 to 2 parts per part of the UV-absorber. Further, the amount of the organic solvent necessary to dissolve said compounds is preferably substantially equal to that of the compound of the general Formula II.

The organic solvent used in the solvent dispersion method may be any of the conventional solvents. Typical examples of the difiicultly water-miscible high boiling solvent include di-n-butyl phthalate, benzyl phthalate, triphenyl phosphate, tri-o-cresyl phosphate, diphenyl-monop-t-butylphenyl phosphate, monophe'nyl-di-p-t-bu-tylphenyl phosphate, diphenyl-mono-o-chlorophenyl phosphate and tri-p-t-butyl phenyl phosphate. Typical examples of the low boiling solvent include methyl acetate, ethyl acetate, propyl acetate, n-butyl acetate, ethyl propionate, carbon tetrachloride, chloroform, methanol, ethanol, dimethylformamide, dioxane and methyl Cellosolve acetate.

Light-sensitive silver halide color-photographic materials of the present invention which are prepared in the above manner have such excellent characteristics as mentioned previously and, when subjected to ordinary color development, can give colored dye images which have been markedly improved in light fastness.

The present invention is illustrated in further detail below with reference to examples.

EXAMPLE 1 A green-sensitive gelatinous silver chlorobromide emulsion containing a magenta coupler was coated on a photographic baryta paper and then dried to form a light-sensitive emulsion layer.

Separately, 0.5 g. of each of the exemplified compounds (8), (12), (17) and (23) of the general Formula II was added to 1 g. of the exemplified UV-absorber (3). This mixture was dissolved at 65 C. in a mixed solvent comprising 0.5 cc. of tri-o-cresyl phosphate and 3 cc. of etyl acetate, and then added into 20 cc. of a 10% aqueous gelatin solution containing saponin. Subsequently, the solution was dispersed by means of a colloid mill, and then mixed with 15 cc. of water, and the resulting gelatin dispersion was coated as a gelatin protective layer on the aforesaid light-sensitive emulsion layer so that the amount of the exemplified UV-absorber became 6.0 mg. per cm. of the emulsion layer and then dried. In the above manner, samples (1) to (6) were prepared. (Provided that the sample (1) contained only the gelatin solution, and the sample (2) contained only the UV-absorber.)

After exposure to light, these samples (1) to (6) were subjected to color development, stopping, hardening, fixing, bleaching-fixing and water-washing, and then dried. Each of the thus treated samples were measured by means of a photoelectric densitometer (reflective type) in green color density of megenta image and stain density of nonimage portion, and then subjected to light fastness exposure test. In the first place, the sample was exposed to direct sunlight for 50 hours by placing its light-sensitive surface toward south at an angle of 45 to the horizontal plane, and then the green color and blue color densities of the thus exposed sample were measured again to calculate the percentage (D/DoxlOO) of the density before exposure (Do) to the density after exposure (D), and the said percentage was deemed as the fading ratio. The results obtained were as shown in Table 4.

TABLE 4 Sunlight exposure Green density loweritnig Stain density a o Sample Amount (Dll ox Before After State of number Content of sample added 100), percent test test surface 1 lltlloneoiffigl.if?.gniaugnni 35 0.03 0.20 Unchanged.

X I 2 "{Trig -gresy l phosghg t ii 1.5 cc 43 Matted Exemplified UV- bsorder 1 g. 3 --{Exemplifisd compound 8 0.5 g. 87 0.03 0. Unchanged.

Trio-eresy1 phosphate 0.5 cc. Exempllfied UV-absorder 3..-. 1 g. 4 -{Exemplified compound 12.-... 0.5 g. 89 0.03 0.06 Do.

Trl-o-cresyl phosphate..- 0.5 cc. Exemplified UV-absorder 1 g. 5--. .-{Exemplified compound 17.- 0.5 g. 89 0.03 0.05 Do.

Tri-o-cresyl phosphate 0.5 cc. Exemplified UV-absorder 3.-.. 1 g. 6 {Exernplified compound 23"--. 0.5 g 90 0.03 0. 04 Do.

Tri-o-cresyl phosphate 0.5 cc.

As is clear from the results shown in Table 4, it is unthe surface due to deposition of the UV-absorber and derstood that in the case of the sample containing the marked in fading of magenta dye and increase in stains, UV-absorber alone [the sample (2)], the solvent-diswhereas the samples (9), (10), (11) and (12) according persed (JV-absorber deposited in the form of crystals, to the present invention were successfully inhibited from so that the sample was matted on the surface, lowered in the fading of dye and the increase of stains on back- UV-absorbing ability as compared with the samples of the ground. present invention [the samples (3) to (6)] and scarcely EXAMPLE 3 inhibited from the light-fading of color image and the A red-sensltive photographic emulsion containing a formgtlon of Si fi the othetr Samples 3 cyan coupler was coated on a photographic baryta paper. .g g fi & e pfresen s i y On the resulted coating, a green-sensitive photographic l f i mm c a mg 0 magen 3 ye an e Increase emulsion containing a magenta coupler was also coated. o 5 EXAMPLE 2 Separately, a gelatin dispersion of such content as shown in Table 6 was prepared by treating, in the same manner To a green-sensitive gelatinous silver halide photoas in Example 1, the exemplified UV-absorber (1) of the graphic emulsion containingamagenta coupler was added general Formula I and each of the exemplified coma solvent dispersion obtained by treating in the same manpounds (8), (14), (17) and (21). This gelatin dispersion ner as in Example 1 the exemplified UV-absorber (5) of was coated on the aforesaid green-sensitive emulsion laythe Formula I and each of the exemplified compounds (6), er so that the amount of the UV-absorber became 0.5 mg. 13), (18) and (26) of the Formula II. Subsequently, per 100 cmfi, and then dried to form an interlayer. the emulsion was coated on a photographic baryta pa- On this interlayer was further coated a blue-sensitive per so that the amount of the UV-absorber (5) besilver chlorobromide emulsion containing a yellow coucame 8.2 mg. per 100 cm In the above manner, sampier. This emulsion had been incorporated with a solvent ples (7) to (12) were prepared. (Provided that the samdispersion of the same content as in the case of the aforeple (7) contained only the emulsion, and the sample (8) said gelatin interlayer, i.e. a solvent dispersion containcontained only the UV-absorber.) ing a mixture of the exemplified UV-absorber (1) and These samples were subjected to the same development each of the exemplified compounds (8), and treatments as in Example 1 and then measured in green a5 Shown in Table COatiIlg the blue-Sensitive color density of image portion and in stain density of emulsion was so eifected that the amount of the UV- white ground. After exposing for 32 hours to Fadeabsorber became 10 mg. per 100 cmfi. 0n the resulting Ometer using a carbon-arc lamp, the samples were again emulsion layer was coated a gelatin protective layer, folsubjected to densitometry to calculate the green density lowering ratios and stain densities thereof. The results obtained were as shown in Table 5.

lowed by drying. In the above manner, samples (13) to (18) were prepared. [Provided that sample (13) was a so-called blank sample which had only a gelatin inter- TABLE 5 Fade-O-meter exposure Green density lowerltng Strain density ra o Amount (D/DoXlOO), Before After State of Sample number Content of emulsion added percent test test surface 7 gon-adlliigltignfi.g -.fi ns 15 0. 04 0. l4 Unchanged.

xemp e -a sor er 1g. {Trl-o-cresyl phosphate 1.0 cc. 22 Matted Exemplified UV-absorber 5-.. 1 g. 9. Exempllfied compound 6. 0.5 g. 88 0. 04 0. 05 Unchanged.

Tri-o-cresyl phosphate. 0.5 cc.

Exemplified UV-absorber 1. g. 10 Exemplified compound 13 0.5 g. 90 0. O4 0. 04 Do.

Trl-o-oresyl phosphate 0.5 cc.

Exemplified UV-absorber 5 1. g. 1 11 Exemplified compound 18..... 0.5 g. 86 0. 04 0.05 Do.

Tri-o-cresyl phosphate. .6 cc. I

Exemplified UV-absorber g. 12 Exempllfied compound 25 0.5 g. 89 0. 04 0.05 D0.

Trl-o-cresyl phosphate 0.5 cc.

As is clear from the results shown in Table 5, the samlayer, and the sample (14) had only the layer of exempliple (8) containing the UV-absorber alone was matted on fied UV-absorber (1).] Each of the thus prepared samples was subjected to the same treatments as in Example 1, measured in blue, green and red densities of image portion and the stain density of white background, exposed to direct sunlight for 50 hours in the same manner as in Example 1 and then measured again in densities 5 to calculate the fading ratio at each density and the stain density. The results obtained were as shown in Table 6.

(OHM-1 wherein R and R are individually hydrogen, alkyl,

TABLE 6 Sunlight exposure Density lowering ratio (D/DoXlOO) Stain density Sam le Amount Before After num er Content ol. sample added Blue Green Red test test 13 Iszemplenlfilaiain 61o bgelelgin lnterlayer and emulsion layer..i 47 45 59 0.08 0.21

Xemp e a sor er 1 g. 14 "{Trl-o-cresyI phosphate. 1.0 co. 53 49 62 07 Exemplifled UV-ebsorber 1 g. 15 Exempllfied compound 8 0.5 g. 92 90 97 0.07 0. 09

Trl-ocresyl phosphate 0.5 cc. Exempllfied UV-absorber 1 1 g. 16 Exemplifled compound 14.- 0.5 g. 96 94 97 0.07 0.10

'Irl-o-oresyl phosphate. 0.5 cc. Exempllfied UV-ebsorber 1 g. 17 Exompllfied compound 17-- 0.5 g. 94 93 93 0. 07 0. l0

'Irl-o-cresyl phosphate. 0.5 cc. Exempllfied IV-absorber 1... 1 g. 18 Exemplified compound 21..-. 0.5 g. 93 90 99 0.07 0. 11

'Irl-cresyl phosphate 0.5 cc.

As is clear from the results shown in Table 6, the samples of the present invention, which had gelatin interlayers and blue-sensitive emulsion layers incorporated with the UV-absorber dispersions according .to the present invention, were prevented from the deposition of UV-absorber and inhibited from the fading at each color density and from the increase of stains.

What we claim is:

1. A light-sensitive silver halide color-photographic material characterized by having a layer incorporated with a dispersion, in an organic solvent comprising a diflicultly water-miscible high boiling solvent or a mixture thereof with a low boiling solvent, of at least one UUV-absorber of the general Formula I wherein R R R R and R are individually a hydrogen or halogen atom or an alkyl, cycloalkyl, alkoxy, aryl, carbalkoxy or alkylsulfonic group, and at least one compound of the general Formula II alkoxy, or acyl group; X is CO or -C00-: and n is 1 or 2.

2. A light-sensitive silver halide color-photographic material according to claim 1, wherein said UV-absorber of the general Formula I is used in amount of 1 to 15 mg. per cm. of the layer.

3. A light-sensitive silver halide color-photographic material according to claim 1, wherein said compound of the general Formula II is used in amount of 0.1 to 2 parts per part of ahe UV-absorber of the general Formula I.

4. A light-sensitive silver halide color-photographic material according claim 1, wherein said layer is the uppermost layer of the photographic material.

5. A light-sensitive silver halide color-photographic material according to claim 1, wherein said layer is at least one of the multi-layered light-sensitive emulsion layers.

References Cited UNITED STATES PATENTS 3,350,204 10/1967 Smith et al. --96-84 R 3,244,524- 4/1966 Trucker 96-84 R 3,533,794 10/1970 Ohi et al. 96--84 R RONALD H. SMITH, Primary Examiner U.S. C1. X.R. 252-300 

